The after-hours medical co-operative stands to lose its main source of funding from mid-2011, when Federal Government incentive payments are scrapped.

Federal Health Minister Nicola Roxon has yet to spell out what will happen to the service and others across Australia, in the two years from when payments are cut and responsibility for after-hours care is handed over to a new network of primary health care organisations, Medicare Locals.

President of the National Association of Medical Deputising Services Australia Stuart Tait has called for bridging funding for the services, which he says will otherwise become financially unviable.

"The money that pays for the Wollongong service finishes in 11 months and there's no new funding until 2013," he said.

"If this problem is not resolved, Wollongong will lose its service."

The Government pays Australia's GPs between $2000 and $6000 in incentive payments each year to take responsibility for 24-hour patient care.

Most daytime GPs in Wollongong and Shellharbour use their payments to "subscribe" to the Wollongong Medical Service Co-Operative (Wollongong Radio Doctor), passing responsibility for their patients' night-time care to a separate pool of rostered GPs.

The Mercury sought clarity on the impact of the changes from Ms Roxon but received no reply.

After-hours services that were meeting their community's needs would continue to attract funding from Medicare Locals, the minister had indicated in a letter to the National Association of Medical Deputising Services earlier.

But she offered no explanation for how they would be funded in the two years before Medicare Locals - restructured divisions of general practice - are formed.

"For many of these services ... funding support that has been available in the past through grants and practice incentive payments will continue to be available, but as a single grant administered through Medicare Locals," she wrote.